Bobbin case for sewing machines



Patented June 10, 1941 BOBBIN CASE FOR SEWING MACHINES Stanley Ernest Frampton, Leicester, England, as-

signor to United Shoe Machinery Corporation, Borough of Flemington New Jersey N. J., a corporation of Application December 16, 1938, Serial No. 246,193 In Great Britain January 4, 1938 Claims.

The present invention relates to shoe sewing machines and is particularly, but by no means exclusively, concerned with outsole lockstitch sewing machines of the hook needle type, one example of which is described in U. S. Letters Patent of Gouldbourn et al., No. 2,056,670 of October 6, 1936.

In U. S. Letters Patent of Gouldbourn et al., No. 1,991,456 of February 19, 1935, there is described a cylindrical bobbin or looking thread case, for a rotary shuttle of a hook needle outsole sewing machine such as is described in Patent No. 2,056,670, having tension devices in the circular wall of the bobbin case which press the thread against an integral portion of the bobbin case wall, and in which time may cause said portion against which the thread is pressed to become worn in such a manner that the tension devices become ineffective. It then becomes necessary to replace the bobbin case by a new one. The bobbin case described in Patent No. 1,991,456 is supported by a pin, secured in the shuttle eccentric to the axis about which the latter rotates, and is held from completely rotating with the shuttle. It has been observed that if the pin in the shuttle, on which the bobbin case is supported, or the bobbin case becomes worn, other portions of the bobbin case are apt to come into contact with the rotating shuttle and to become so worn that the bobbin case is quickly rendered unfit for use.

The various objects of the present invention are to simplify the constructions and prolong the useful life of a bobbinor thread case in a machine such as is above referred to.

In an illustrative embodiment of the present invention there is provided a cylindrical bobbin or locking thread case having all the thread en-, gaging parts including thread tensioning means and a wear member against which the tensioning means presses the thread, supported in a circular wall and readily renewable when worn. To avoid difficulty with projecting corners or angular edges on which particles of thread or other matter may accumulate, as hereinafter described, the surfaces of the wear member are curved and form continuations of the circular wall of the bobbin case. 'In the preferred form of the invention, the wear member is provided with a plurality of surfaces any of which may be located at a position to support the thread. In carrying out this feature of the invention, the wear member is retained in position by means embracing the circular wall of the thread case, and such an arrangement is of advantage whether the thread tension device is renewable or not. In carrying out this feature of the invention, the wear member is grooved to provide a surface level with a peripheral groove in the circular wall of the bobbin case for receiving the means to retain the wear plate in place.

The renewable wear member of the illustrative embodiment has in its holes through one of which the shuttle thread passes from a thread reel in the case to the tension device, the latter being arranged in a groove extending around the outer circular face of the case. The features of the invention include the use of the same or a second renewable wear member in the curved wall of the bobbin case, forming part of the thread tension device against which the shuttle threadis pressed as it is passing from the bobbin case, said member or members being renewable by changing or reversing their individual positions. An additional renewable wear member is provided in one form of this feature, instead of the usual hole in the front face of the bobbin case, from which the shuttle thread passes after it leaves the tension device.

The bobbin case illustrated in the drawing is also provided with a renewable sleeve which receives and forms a bearing for the pin in the shuttle, on which pin the bobbin case is rotatably mounted.

The above and other objects, and the several features of the invention will become apparent to those skilled in the art from a consideration of the following description, given by way of example and with reference to the accompanying drawing.

In the drawing, Figure l is a view illustrating the peripheral circular face or wall of a cylindrical bobbin case embodying the present invention, as it would appear if laid out fiat, with renewable bobbin thread engaging devices thereon; Figure 2 is a perspective View showing various parts of the bobbin case separated from each other; Figure 3 is a sectional view on an enlarged scale, taken along the line 3--3 of Figure 1; Figure 4 is a view of part of the circular peripheral face or Wall of the bobbin case, as shown in Figure 1, with renewable wear device of a different form; Figure 5 is a view of part of the peripheral face of the bobbin case as shown in Figure 4, but Without the renewable devices; Figures 6 and '7 are views in front and side elevation, respectively, of the reversible and renewable wear device having in it holes through one of which the thread passes as it leaves the inside of the bobbin case; Figures 8 and 9 are similar views of another reversible and renewable wear device cooperating with the thread tension; and Figure is a sectional View of the bobbin case.

The illustrated bobbin or locking thread case i is of cylindrical or similar shape and is provided with shuttle thread contained in a reel or other thread supply package of usual construction rotatably mounted in the bobbin case, as

indicated by dot-dash lines 5 of Figure 10. The

bobbin case has formed in it a central boss 2 in which is a renewable sleeve 3,arranged to form" a bearing for a pin (not shown) in the shuttle, on which pin the bobbin case is rotatablymounted and which may readily be replaced when wear occurs. The sleeve is formed with a shoulder within the thread case to locate its endwise position in the bobbin case, and with an enlarged" portion extending beyond the boss 2 upon which is rotatably supported the bobbin reel or other thread package.

The bobbin case embodying the present invention has formed in its circular side wall faces "I, 8' (Fig. 3) in which is removably supported a single renewable wear member in the form of a curved perforated block ii. The curvature of the block it along its inner face, as shown in Figure 3, is such that it forms a continuation of the inner circular wall of the bobbin case. The outer face of the block is also curved and grooved to provide surfaces substantially level with the bottom face of a peripheral groove 53 extending around the bobbin case.

The block. H is held. in an opening 6 by yielding retainers in the form of a circular tension member I5, and a circular adjusting member I1, to be described more fully hereafter. The members it: and i7 embrace the bobbin case within the groove i3 overlapping the block H to secure the block in place.

The block H has formed in it two perforations or holes is through one of which thread from the reel in the bobbin case passes. The block H has formed on its wear faces 2i at right angles to the bottom surface of groove i3 against one of which wear faces the shuttle thread is pressed by'the tension member 15, the faces 2| being slightly undercut and rounded, as indicated at 23 (Fig. 2) at an end of each and. sharp cornered at the other end, so that when the block is in place, in the bobbin case, there will be an accurate alinement between'the two. The shuttle thread, after passing between the tension member i5 and one of the faces 2!, passes over the rounded end of a face 2| towards one end of the thread case through an axial hole or eye 25 in a circular yielding guide member 27 which is positioned in a groove Ml extending around the circular wall of the thread case. When the sides of hole 25 in the member 21 wear unduly, the member may readily be renewed by springing the ends apart so that it maybe removed from the groove 29. Also, when one ofthe holes it and/or one of the faces 21 becomes worn, the member H may be removed andjbe replaced on the bobbin case with the other 'hole' and face reversed in position so as to be engaged by the thread. When both holes and faces become worn, the member may readily be renewed.

As the locking thread leaves the bobbin reel 5 in the embodiment of the invention illustrated in Figures 4 to 9 inclusive, the thread passes over a guide pin 35 secured in the bobbin case and extending across an opening 3! formed partly'in the peripheral wall and partly in the front wall of the case. The pin 35 may readily be replaced by a new one if it becomes worn by the passing of the shuttle thread over it in a direction axially of the thread case. This bobbin case has also formed in it two circular openings 33 and 35 which intersect each other, as shown in Figure 5, and each opening is counter-bored to form supporting faces 31 and (iii.

In the opening 35, and supported by the face 35-], is a "disc-shaped renewable wear member or block 4i (Figures 6 and 7) which has formed in it two holes 43 through one of which the shuttle thread passes, as shown in Fig. 4. The member ll has a comparatively thin central portion in which are formed the holes 43, and at each end of the central portion is a flange arranged to be supported on the face 39. The inner face 45 of the central portion of the member 4i is substantially level with the inner peripheral face of the bobbin case, and the outer face ll -of the central portion is substantially level with the bottom face of a groove similar to the groove itextending around the bobbin case.

In the opening 33, and supported bytheface 3? is another disc-shaped renewablewear member or block as. The member 49 has a central portion; the inner face 5! of whicnisfsubstana tia'lly level' with the innerperipheral' face'of the bobbin caseand the'outer face '53'of which is substantially "level with the bottom face of the groove 13in the bobbinpase. The member 49 has formedon it'faces against one of which the shuttle thread is pressed by'a tension mem-. ber, similar to the'member l5above referred to, after it leaves the 'hole 53in the member 4!; as shown in'Figure' 4. The faces 55 are slightly undercut and rounded, as indicatedat .51; to provide a rounded corner around which the thread passes. When one of the hole's43 or. faces tilbecome" worn, the position of either of the members ii and '59 on the bobbin case may.

readily be reversed to bring any other holeor face of me'mber 4i 'into operative position and, when both holes and faces of'the member are worn, the worn members may readily and comparatively cheaply be replaced by new ones.

The members 4i and 49 are prevented from rotating in the circular openings 33 and 35 by their engagement with eachother, the corners 5d of member El beingbevelled 01f -somewhat to provide faces for engagement with the member Q9, and the two members are held in. the

openings byiretainer member-s similar to the aforesaid tensionmember lSand tension adjustin'g member ll, above referred to, which extend partly around 'the bobbin case i-in the groove l3 The member If: in 'bothmodifications'has-0n it a projection '65 which enters a rece'ssiri one wall of the groove i3 and prevents the member is?" from moving "around the bobbin case. The

tension member !5 also has another projection 63 at one end of it which engages in one of a series otrec'esses 65 formed in the adjusting member H. The otherend of the member l5 presses the shuttle thread 'against'one face 'on' the wear member. The member i! has ata pered portion-6i, one face of which engages a curved part lid 'of the member l5; If the mem'-' ber ll isadjusted around the bobbin case'the' tapered portion 6'? causes the member i5' to press more or less firmly against the thread and 'thusvaries the tension" on the thread. The adjusting member i1" is held in adjusted'posh tion by the engagement of one of the recesses 65 with the projection 63.

The form of the renewable part II shown in Figures 1 and 2 is somewhat cheaper to produce than the two parts 4| and 49 shown in Figures 4 to 9 inclusive, and the hole in the guide member 21 provides a considerably greater wearing surface than the pin 30, the hole 25 being so arranged in the member 21 as to provide as much material as possible between the hole and the outer surface of the member, as shown in Figure 1, to be worn away before the member requires renewing.

In the illustrative embodiments there are thus provided a durable bobbin case of comparatively simple and inexpensive form with readily renewable parts which are engaged by the shuttle or looking thread and are liable to become worn by the pressing of the thread against them as it leaves the case.

Having now described the nature of the present invention, what is claimed is:

1. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination with a cylindrical bobbin thread case, readily renewable thread engaging parts mounted in a circular wall of the thread case comprising a tension device, and a wear member having a surface level with a surface of the thread case against which the tension device presses the thread.

2. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination with a cylindrical bobbin thread case, readily renewable thread engaging parts mounted in a circular wall of the thread case comprising a tension device, and a wear member against which the tension device presses the thread comprising a curved block provided with a plurality of surfaces, any of which may be located in a position to support the thread along that portion pressed by the tension device.

3. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination with a cylindrical locking thread case, readily renewable thread engaging parts in the thread case comprising a wear member along which the thread passes, and means embracing a circular wall of the thread case for holding the wear member in place.

4. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination with a cylindrical locking thread case, readily renewable thread engaging parts in the thread case comprising a wear member along which the thread passes, a yielding tension device embracing the thread case and acting to press the thread against the wear member and to hold the wear member in place.

5. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination with a cylindrical locking thread case having a peripheral groove about its circular wall, readily renewable thread engaging parts in the circular wall of the thread case comprising a block provided with surfaces level with the bottom face of the groove in the circular wall, and means within the groove of the thread case overlapping the block to hold it in place.

6. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination, a cylindrical locking thread case having a peripheral groove about its circular wall, readily renewable thread engaging parts in the circular wall of the thread case comprising a block provided with a wear face in alignment with one lateral edge of the groove in the thread case, and means mounted within the groove for pressing the thread against said wear face and for holding the block in place.

'7. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination, a cylindrical locking thread case having a peripheral groove about its circular wall, readily renewable thread engaging parts in the circular wall of the thread case comprising a block provided with a wear face in alignment with one lateral edge of the groove in the thread case, means mounted within the groove in the thread case for pressing the thread against the wear face of the block and for holding the block in place, and renewable means to direct thread passing from the wear face'of the block at right angles to the wear face axially towards one end of the thread case.

8. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination, a cylindrical locking thread case having a peripheral groove about its circular wall, readily renewable thread engaging parts in the circular wall of the thread case comprising a block provided with a wear face in alignment with one lateral edge of the groove in the thread case, means mounted within the groove in the thread case for pressing the thread against the wear face of the block, and for holding the block in place, and a yielding renewable member extending around the circular wall of the thread case and having a thread eye for guiding the thread passing from said wear face axially towards one end of the thread case.

9. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination, a cylindrical locking thread case having a peripheral groove about its circular wall, readily renewable thread engaging parts in the circular wall of the thread case comprising a block provided with a wear face in alignment with one lateral edge of the groove in the thread case, means mounted within the groove in the thread case for pressing the thread against the wear face of the block, and for holding the block in place, a renewable guide member for directing the thread passing from said wear face axially towards one end of the thread case, and a renewable wear member having rounded corners about which the thread passes from the block to the guide member.

10. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination with a cylindrical locking thread case, readily renewable thread engaging parts in the thread case comprising a wear member having angularly disposed surfaces along one of which the thread passes, and a tension member for pressing the thread against the wear member and for engaging the other surface of the wear member to hold it in place.

11. A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination with a cylindrical locking thread case having a peripheral groove, readily renewable thread engaging parts in a circular wall of the thread case comprising a grooved wear member having angularly disposed surfaces along its grooved portion, and a circular tension member embracing the groove in the thread case to press the thread against one of the surfaces of the wear member and to hold the wear member in place by engaging another of said surfaces.

12. A shuttle thread supply .device for. a lock.

stitchr'shoe sewing machine having, in combinae. tionwith a cylindrical locking thread case, readily 1 renewable thread engaging parts in. the thread case, comprising means for :directingthe thread circumferentially along a circular side Wall of the thread-case, and a replaceable pinextending across anopening in the thread casefor guiding the thread axially 'of the thread case along said sidewall. v r

13; A shuttle thread supply device for a lockstitch shoe sewing machine having, in combination with a cylindrical bobbin thread case, read, ily renewable thread engaging parts mountedin a circular Wall of the thread case comprisinga tension device and a renewable block provided with holes arranged to be located readily intone of a number of positions to permit the thread from within the thread case to pass through any one of the holes to the tension device depending upon the position of the block.

' l4. A shuttle thread supply device .for. a lockstitch shoe sewing machine having,v,inr combinatio'nrwi'th a'cyiindricalbohbin thread case, readily renewable thread engaging parts mounted in a circularlzwalllof the threadrcase comprisinga tensionvdevice and a renewable block having. holeslforlguidingrthe threadthroughthe Wall of the thread case, said block being so shaped that itwill fit intheathread case in more than one position with one of the holes located to guiderthe threadin any ofsaid positions.

155Abobbin thread supply device for a lock: stitch shoe sewing machine having, in combina-' tion, a cylindrical locking thread case provided with a central bearing on which the thread case is rotatably supported, and a renewable sleeve.

within thetbearing formed with an enlarged shoulder portion extendinglbeyond the bearing torotatably support athread supply reel.

STANLEY: ERNEST FRAMPTONJ 

